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ME.  J.  L.  CLAEKE  ON  THE  INTIMATE  STEHCTUEE  OF  THE  EE  A IN. 
which  send  out  their  processes  both  transversely  and  longitudinally ; c,  are 
fibres  radiating  from  the  restiform  ganglion,  and  from  the  decussation  of  the 
anterior  pyramid  of  the  opposite  side,  into  the  white  substance  of  the  resti- 
form body ; a vesicular  tract  imbedded  in  the  lateral  column  on  the  outer 
side  of  the  olivary  body.  The  group  of  small  cells,  resting  on  the  back  of  the 
anterior  pyramid,  form  the  commencement  of  the  ohvaiy  body ; I,  I,  the 
non-decussating  portions  of  the  anterior  pyramids ; their  posterior  halves  are 
divided  into  numerous  bundles  by  the  decussating  fibres ; a group  of  large 
stellate,  oval,  fusiform,  pyriform  and  crescentic  cells  imbedded  in  the  lateral 
column  amongst  the  network  represented  on  the  opposite  side  of  the  figure : 
the  whole  of  this  netv/ork,  enclosing  longitudinal  bundles,  is  interspersed  with 
cells  of  different  shapes  and  sizes,  which  frequently  embrace  the  bundles,  and 
send  their  processes  longitudinally  and  transversely  in  different  directions. 
Behind  and  on  each  side  of  the  central  canal  is  the  commencement  of  the 
nucleus  of  the  spinal-accessory  nerve ; and  in  front  of  it,  on  each  side,  is  that 
of  the  hypoglossal  nerve : x is  the  commencement  of  the  superficial  arciform 
fibres. 
PLATE  XV. 
Fig.  24.  Longitudinal  section  of  the  human  olivary  body,  mth  part  of  the  olivary 
column,  showing  the  convolutions  of  the  grey  lamina,  or  corpus  dentatiiin. 
Fig.  25.  A series  of  convolutions  of  the  grey  lamina  of  the  human  olivary  body ; on  the 
left  side  the  cells  of  the  lamina  are  represented : — O,  O,  part  of  the  central 
white  nucleus ; Q,  Q',  Q,  part  of  the  antero-lateral  column. 
Fig.  26.  Anterior  pyramids,  z,  ^,  and  olivary  bodies,  Jc,  k,  of  the  Sheep : on  the  left 
side  the  arciform  fibres  are  seen  winding  through  them. 
Fig.  27.  Anterior  pyramids  and  olivary  bodies  of  the  Cat:  the  olivary  commissure, 
joined  by  the  arciform  fibres,  is  seen  decussating  across  the  raphe. 
PLATE  XVI. 
Fig.  28.  Transverse  section  of  the  human  medulla  oblongata  through  the  lower  paid  of 
the  olivary  bodies : — r,  spinal-accessory  nucleus ; g",  spinal-accessory  nerve ; 
t,  hypoglossal  nucleus. 
Figs.  29,  30,  31,  32.  A series  of  similar  sections  Aom  the  point  of  the  calamus  scrip- 
torius  to  the  upper  roots  of  the  vagus  nerves  {f) : — ar,  superficial  arciform 
fibres. 
Fig.  33.  Transverse  section  of  the  medulla  oblongata  of  the  Sheep,  immediately  below 
the  point  of  the  calamus  scriptorius  •. — r,  r,  "Nugal  nuclei  joined  by  their  trans- 
verse commissure,  which  forms  the  roof  of  the  upper  extremity  of  the  canal. 
